M.J. Simões

Pinealectomy changes rat ovarian interstitial cell morphology and decreases progesterone receptor expression.

The aim of this study was to evaluate the rat ovarian morphological and function changes after pinealectomy (px). Two months after px ,young female Wistar rats were sacrificed and the right ovaries were analysed morphologically and the left ovaries were used for steroid receptor binding experiments. Blood was collected and steroid hormone and melatonin levels were measured using radioimmunoassay kits. Results revealed that in the px group the rat ovaries had an increase in the number of atretic follicles and interstitial cells. These cells showed hyperactivity features on transmission electron microscopy and morphometric analysis (p < 0.05 compared with control and sham groups). Px-group serum showed an increase in estradiol (p < 0.05) and a decrease in progesterone levels (p < 0.05) compared with other groups. Moreover ,progesterone receptor expression was lower than control and sham groups (p < 0.05). We postulate that pinealectomy leads to many morphological alterations of rat ovaries that are associated with functional changes in steroidogenesis and a decrease in progesterone receptor expression.

Effect of Estrogen–Progestogen Hormonal Replacement Therapy on Periurethral and Bladder Vessels

Abstract: This study assessed the effect of hormone replacement therapy using estrogens and/or progestogens on the number of vessels in the proximal and distal urethra, vesicourethral junction and bladder of castrated adult female rats. Forty-five virgin adult rats (Rattus norvegicus albinus) castrated for at least 30 days were used. They were assigned to five groups; group I (control) received no medication; the others received via the subcutaneous route, respectively, 17-β-estradiol (group II), medroxyprogesterone acetate (group III), a maize oil and benzyl acid solution – placebo (group IV) and 17-β-estradiol combined with medroxyprogesterone acetate (group V), for a minimum of 28 days. Increased vascularization throughout the urinary tract, except in the distal urethra, was found following estrogen replacement alone. In the group that received combined estrogens and progestogens, no increase was found. It was concluded that estrogen replacement in castrated rats significantly increased the number of vessels in the lower urinary tract.

Effects of allopurinol on ischemia and reperfusion in rabbit livers.

In this work, we evaluated the effects of allopurinol (ALO), an inhibitor of xanthine oxidase (XO), on hepatic lesions caused by ischemia/reperfusion (I/R) in the rabbit liver. Rabbits were pretreated with ALO (10 mg/kg IV) or saline solution 0.9% before the hepatic I/R procedure. The effects of ALO on hepatic injury were evaluated before and after I/R. A standard, warm hepatic I/R procedure caused profound acute liver injury, as indicated by elevated serum aspartate aminotransferase, alanine aminotransferase, and lactic dehydrogenase levels, as well as a high apoptotic cell count. All of these changes were reversed by the administration of ALO before the hepatic I/R procedure. In conclusion, ALO exerted protective effects on hepatic I/R lesions. This protective effect of ALO was probably associated with blocking the generation of superoxide anions during the hepatic I/R procedure by inhibiting XO activity.

Protective Effects of Heparin on Hepatic Ischemia and Reperfusion Lesions in Rabbits

Because the role of heparin (HEP) in hepatic ischemia/reperfusion (I/R) injury is still not fully understood, we investigated the effects of treatment with HEP on hepatic I/R injury in rabbits. For I/R procedures, the portal vein and hepatic artery were occluded by a metallic clamp to promote ischemia. The clamp was removed after 30 minutes to allow reperfusion. Rabbits undergoing the I/R procedure were treated with HEP (100 U/kg) or saline solution 0.9% (SS). When compared with levels before I/R, the serum aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, levels were increased by the hepatic I/R procedure, among rabbits treated with SS or HEP. However, the increase in these enzymes was lower among rabbits treated with HEP. Histologic analysis of hepatic tissue of rabbits undergoing I/R and treated with SS showed marked lesions in the central lobule with significant inflammatory infiltration. In contrast, a significant reduction in lesions caused by I/R was observed in the livers of rabbits treated with HEP. After starting reperfusion, we visualized apoptotic cells with nuclear staining among rabbits submitted to I/R and treated with SS, but not those treated with HEP. These results suggested that HEP was able to attenuate hepatic lesions caused by I/R in the livers of rabbits.

Effects of tamoxifen on the breast in the luteal phase of the menstrual cycle

Objectives: The effect of tamoxifen on cyclic mastalgia and on chemoprophylaxis against breast cancer is little known, mainly due to the difficulties in studying the normal human gland. We proposed to evaluate the mitotic index and the nuclear volume of the lobule of women medicated with tamoxifen only during the luteal phase of the menstrual cycle in order to observe the effect of tamoxifen on the normal human mammary gland. Methods: Twenty‐four premenopausal women with fibroadenoma diagnosed via biopsy were studied. The phase of the cycle was determined by the date of menstruation and serum progesterone level in the luteal phase (≥3 ng/ml). The patients admitted to the study and were given written informed consent to participate in the investigation, which was previously approved of by the hospital Ethics Committee. Patients were divided at random into two groups: Group I consisted of 12 untreated women (control) and Group II consisted of 12 patients treated with 20 mg/day tamoxifen for 10 consecutive days beginning on the 13th day of the menstrual cycle. In both groups, the patients were submitted to biopsies of the nodule and of a 1‐cm3 fragment of adjacent mammary parenchyma between the 23rd and 26th day of the cycle. The mitotic index (number of mitoses/1000 nuclei counted) and mean nuclear volume (mean of 10 nuclear volumes for each case) were measured. Results: No mitosis was observed in Group II. There was a reduction in the mean nuclear volume in Group II (Mann–Whitney test). Conclusions: Tamoxifen, when administered only during the luteal phase of the menstrual cycle, significantly reduces the nuclear volume and mitotic activity of the epithelium. This data demonstrates an antagonistic action of tamoxifen on estrogen even when administered for short periods of time.

Remote ischemic preconditioning on neovascularization and follicle viability on ovary autotransplantation in rats.

PURPOSE Verify the optimum remote vascular occlusion time to reduce ovarian injury in autologous transplants in rats. METHODS Twenty-four adult female rats were assigned to four groups: GC (control group): bilateral oophorectomy followed by ovary transplant; GIPC (ischemic preconditioning group): remote ischemic preconditioning at the iliac artery for 5, 10, and 15 minutes (GIPC-5, GIPC-20, and GIPC-15) previous to bilateral oophorectomy and ovarian transplantation. The right ovary was fixed in the retroperitoneum. Euthanasia was performed 4 days after the surgical procedure. The follicles were counted and classified as developing versus atretic. The immunohistochemical assay identified vascular factor of endothelial growth (VEGF) in the ovarian stroma and assessed the proliferation capacity by means of the Ki-67 in the ovarian follicles. RESULTS Every group showed an inflammatory infiltrate, luteous body, and ovarian follicles in several phases of development. The ischemic preconditioning groups displayed greater amounts of viable ovarian follicles and increased vascularization and vasodilatation than the control group. GIPC-15 showed the highest amount of viable follicles compared to the others (P < .05 GIPC-15 vs GC; GIPC-15 vs GIPC-5). More VEGF-labeled cells were observed in GIPC-10 than the control group (P < .05, GIPC-10 vs GC). The proliferation index assessed by Ki-67 marking showed GC: 80%; GIPC-5: 76%; GIPC-10: 67%; and GIPC-15: 64% (P > .05). CONCLUSIONS The PCI-15 cohort seem to be the most adequate timing to achieve functional support and preservation of a greater number of viable ovarian follicles.

Estrogenic activity of tamoxifen on normal mammary parenchyma in the luteal phase of the menstrual cycle

Objectives: Tamoxifen, an anti‐estrogenic drug used in the adjuvant treatment of breast cancer, deserves more investigation for the determination of its efficacy as a prophylactic agent against breast cancer in high risk women. Thus, the action of tamoxifen on the human mammary gland was studied by measuring the number of lysosomes in normal mammary epithelium during the administration of tamoxifen. Methods: Tamoxifen was administered only during the luteal phase of the menstrual cycle to avoid interference with corpus luteum formation. A fragment of breast tissue adjacent to a fibroadenoma was obtained during surgery from 35 premenopausal women aged 15 to 37 years who had been eumenorrheic for at least 6 months; 18 of these patients were treated with tamoxifen and 17 were used as controls. Lysosome counts were performed under the light microscope on slides submitted to the acid phosphatase cytochemical technique and the data were analyzed statistically by the Mann‐Whitney test. Results: The fragments from the group treated with tamoxifen showed a significant decrease in lysosome numbers. Conclusions: Tamoxifen administered after ovulation significantly decreases the number of lysosomes in the cells of normal mammary epithelium, demonstrating the antiestrogenic effect of the drug on this target tissue.

Effect of Remote Ischemic Preconditioning on Rat Estradiol Serum Levels and Follicular Development After Ovarian Transplantation

PURPOSE The purpose of this study was to evaluate estradiol serum levels and follicular development in rats subjected to ovarian autologous transplantation with or without remote ischemic preconditioning (R-IPC). METHODS Seventy-two adult female Wistar EPM-1 rats were distributed into 3 groups: (1) controls; (2) ovarian transplantation; and (3) ovarian transplantation + R-IPC. The groups were divided into subgroups, according to the prefixed date for euthanasia: 24 hours, 48 hours, 72 hours, and 7th postoperative day (PO). R-IPC was performed by clamping the common iliac artery for a 15-minute period of ischemia followed by 15 minutes of reperfusion, before undergoing ovarian transplantation. The graft was fixed to the retroperitoneum with a simple 8-0 prolene thread. Blood samples were collected from the vena cava. For evaluation of follicular development, the ovarian follicles were classified as immature and mature follicles besides corpora lutea. Only the viable follicles and functioning corpora lutea were counted. RESULTS At 72 hours, the R-IPC group showed higher estradiol values than the other groups, which were similar. After 24 hours the mean values were similar among all groups, and at 48 hours the R-IPC group was similar to the transplanted group without IPC. Animals undergoing R-IPC showed superior morphologic aspects, but 7 days after transplantation the morphology was worse in all groups. R-IPC enhanced the number of immature follicles at 48 hours (P > .05) and number of mature follicles from 24 hours to 48 hours after transplantation (P < .01). Functioning corpora lutea number was increased as well. CONCLUSION R-IPC increased the estradiol levels in autologous ovarian transplants associated with better graft morphology and more mature follicles.

Estudo comparativo entre a sutura contínua e a com pontos separados na parede abdominal de ratos

The purpose of the experiment was to compare the continuous and interrupted techniques of abdominal clousure. It was used 48 male rats Wistar to realize longudinal laparotomies with a standardized technique. In 24 of them, the abdominal wall was closed by continuous suture and in 24 of them closed by interrupted suture. All of them using polidioxanone. In the 7th and 14th postoperative day, 12 animals of each group were submitted to euthanasia and the front abdominal wall was removed (without skin) and divided in two segmentes (cranial and caudal), one for hystological analysis with an objective measurament og collagenous and another to the test of tensile strength by tensiometer. The resultant data were submitted to statistical analysis. It was conclued that in the 7th day , the abdominal wall closed by interrupted technique is more resistant without significant diferences on collagenous density than the other closed by interrupted, and at the 14th day the results are similar, in rats.

Efeito da N-acetilcisteína no pulmão após isquemia hepática em ratos

In ischemia and reperfusion syndrome, the lungs can be the target of remote lesion as it happens in cases of shock, trauma, or liver transplantation. Objective: The aim was to evaluate the effect of N-acetylcysteine (NAC) in the lungs following liver ischemia. Methods: 12 male EPM-1 Wistar rats were used, divided into two groups of six animals each (control and experimental). Animals of both groups received anesthesia with ketamine and xylazine. Longitudinal medial incision was performed for identification of the hepatic hilum and caudal vena cava. 5% glucose solution was injected in the control group 15 minutes before hepatic hilum clamping, and NAC dissolved in the same solution was injected in the experimental group. The animals were maintained in hepatic ischemia during 30 minutes, followed by surgical resection of the lungs for histological evaluation, stained by HE. Results: Cavity collapse, neutrophil-permeation, vessel congestion, and hemorrhagic areas were observed which are compatible with systemic repercussion of liver ischemia, in all animals of both groups. Conclusion: NAC does not protect lungs from morphological changes following liver ischemia.